Device and display device using the same

Abstract

Provided is a lighting device that inputs a light from a light source from a side surface of a light guide body, and outputs the light from an upper surface of the light guide body, in which a recess is formed on a light input surface of a light guide plate so as to face the light source, and a paraboloid extending in a radial pattern in a light output direction from a light output part of the light source is connected to the light input surface. Prisms arranged on a light output surface of the light guide body are disposed up to an area closest to the light source wherever possible. With the above-mentioned configuration, an output of the light of components perpendicular to the light output surface of the light guide body remarkably increases, and brightness of the lighting device can be enhanced without using a prism sheet.

1 . A lighting device, comprising:
 a light guide body which includes a light input part and a light emitting part, and guides a light input from a light input surface of the light input part to output the light from a light output surface of the light emitting part;   a light source which outputs the light to the light input surface; and   a recess formed on the light input surface so as to face the light output part of the light source,   wherein the light input part has the light input surface, and a paraboloid extending in a radial pattern in a light output direction from a light output part of the light source.   
   
   
       2 . A lighting device according to  claim 1 , further comprising a plurality of prisms formed on the light output surface in a direction orthogonal to the light input surface. 
   
   
       3 . A lighting device according to  claim 1 , further comprising a plurality of prisms formed on the light output surface so as to cross each other. 
   
   
       4 . A lighting device according to  claim 2 , wherein each of the plurality of prisms has a cross-sectional configuration of a triangle having a vertex angle falling within a range of from 40° to 170°. 
   
   
       5 . A lighting device according to  claim 4 , wherein the plurality of prisms having different vertex angles are arranged. 
   
   
       6 . A lighting device according to  claim 2 , wherein each of the plurality of prisms has a cross-sectional configuration of a semi-circle. 
   
   
       7 . A lighting device according to  claim 2 , further comprising the plurality of prisms formed on the light input part,
 wherein the plurality of prisms formed on the light output surface of the light emitting part and the plurality of prisms formed on the light input part are different in configuration from each other.   
   
   
       8 . A lighting device according to  claim 1 , wherein the recess has a configuration of any one of a triangle, a semi-circle, and a polygon of a rectangle or more. 
   
   
       9 . A lighting device according to  claim 1 , further comprising reflection structural bodies formed on a lower surface of the light guide body at regular pitches,
 wherein heights of the reflection structural bodies are increased as the reflection structural bodies are spaced apart from the light source.   
   
   
       10 . A lighting device according to  claim 1 , further comprising reflection structural bodies having the same height formed on a lower surface of the light guide body,
 wherein pitches of the reflection structural bodies are reduced as the reflection structural bodies are spaced apart from the light source.   
   
   
       11 . A lighting device according to  claim 9 , further comprising a structure for suppressing a total area of reflection surfaces of the reflection structural bodies, which is formed on the lower surface of the light guide body. 
   
   
       12 . A lighting device according to  claim 11 , further comprising a plurality of the structures arranged at given pitches. 
   
   
       13 . A lighting device according to  claim 11 , wherein the structure has a smaller cross-sectional area as the structure is spaced apart from the light source. 
   
   
       14 . A lighting device according to  claim 11 , wherein the structure includes a vertical prism having a long side in the light output direction of the light source. 
   
   
       15 . A lighting device according to  claim 1 , wherein the paraboloid has a polygonal configuration formed of a plurality of flat surfaces which are combined at angles with each other. 
   
   
       16 . A display device, comprising:
 a light guide body which includes a light input part and a light emitting part, and guides a light input from a light input surface of the light input part to output the light from a light output surface of the light emitting part;   a light source which outputs the light to the light input surface;   a display element which performs display by using the light output from the light output surface; and   a recess formed on the light input surface so as to face the light output part of the light source,   wherein the light input part has the light input surface, and a paraboloid extending in a radial pattern in a light output direction from a light output part of the light source.